term1 Definition1term2 Definition2term3 Definition3
Please sign in to your Google account to access your documents:
Producers
Plant and algae photosynthesise
Glucose synthesised have bonds which contain light energy and chemical potential energy
Glucose formed can be used in respiration to produce water and carbon dioxide and water heat energy OR glucoses can be used to make other molecules eg starch, cellulose, amino acids which are the plants BIOMASS.
Biomass definition
Biomass is all the biological molecules made by the plant and are not immediately used for respiration. It represents the growth of the plant.
How is biomass measured?
It's a measure of the mass of carbon in the biological molecules
Measured as dry mass
Can be used to measure the energy value as each molecule making up the biomass strores energy in their bonds.
Practical estimation of dry mass
1. Heat in a low temp oven to evaporate water in the tissues. (No higher than 100°c or else dry mass will burn and energy cannot be calculated)
2. Continue measuring biomass until there is no further change.
3. Calculate biomass in Kgm-2y-1
4. Carbon content estimated as 50% of dry mass.
Why do we use dry biomass rather than wet biomass?
Water content of different organisms will vary. Water is not made by the plant In photosynthesis so therefore water is not biomass.
What are the units for dry mass and the energy value?
What is the explanation of the units for dry mass and energy value?
So that we can FAIRLY COMPARE biomass produced in different plants in different habitats. Taking in to account:
- The size of the area it has come from (m-2/ metre)
- the time period (yr-1) growth rates vary with the time of year so take into account the whole year.
Practical technique for obtaining energy value in dry biomass
Biological molecules store chemical potential energy.
Dried biomass is put in a calorimeter
Dry biomass is then combusted
Energy released is used to heat water.
The change in water temp is used to calculate the energy released.
Gross primary production : GPP
The total amount of light energy captured in photosynthesis and stored in molecules as chemical potential energy.
Respiration (R) definition
The amount of energy lost from the plant in respiration. This returns to the environment as waste heat.
Need help typing ? See our FAQ (opens in new window)
Please sign in to create this set. We'll bring you back here when you are done.
Discard Changes Sign in
Please sign in to add to folders.
Sign in
Don't have an account? Sign Up »
You have created 2 folders. Please upgrade to Cram Premium to create hundreds of folders!